A linkage-type air suspension system for supporting either a front steer axle or a rear drive axle includes a lower structure assembly which combines the lower control rods, a transverse rod and a stabilizer control system which functions as a single structure. The transverse control system includes a pair of lower beams which have one end thereof pivotally connected to mounting brackets secured to the frame members of the vehicle by pivot bearings. The other ends of the lower beams are pivotally connected to axle and wheel supports. A transverse control is secured to and extends between the lower beams.